Manually settable relay



May 6, 1958 TMCRMIIAT W. A. RAY

MANUALLY SETTABLE RELAY Filed July 27. 1954 INVENTOR, MLL/A/ A). PAY

ATTORNEY United rates Patent @r" MAN UALLY SETTABLE RELAY William A. Ray, North Hollywood, Calif., assignor to General Controls Co., Glendale, Calif., a corporation of California Application July 27, 1954, Serial No. 446,101

8 Claims. (Cl. 200-87) This invention relates to electromagnetic switch-actuating devices, or relays, adapted to be energized by power from the electric service lines and controlled by means such as a thermostat or similar control device; the invention relating more particularly to improved means for actuating the switch manually in the event of failure of the electric power, and including means for automatically returning the switch to condition for normal actuation by the relay when the power is restored.

In previous arrangements of this kind, to actuate the switch during failure of the electric power the armature is moved manually to switch-actuating position by means of a cam arranged so that it is retained in latched position by the armature, against a force biasing the cam to inactive position, while the relay is unenergized. The switch is arranged so that it is actuated by means of the cam when the armature is in a position such that it can move somewhat farther, when the power is restored, to effect release of the cam. In this prior-art arrangement the normal operative stroke of the armature must be relatively long (about 0030-0060 inch in a typical relay) in order to permit the farther movement of the armature necessary to efliect unlatching of the manual switch-actuating cam.

Inasmuch as power for operating the relay is derived from the service lines, the small amount of additional power required to attract the armature through a longer distance is of no consequence. However, an unobvious but very significant disadvantage of the prior-art relay is the relatively loud click produced by the impact of the armature on the pole-face in normal operation. Such noise is particularly noticeable and annoying at night when the relay is employed in connection wtih the automatic control of a domestic heating or cooling system.

it is therefore an object of this invention to provide a switch-actuating relay of the manually-settable type described wherein the armature moves through only the same distance as it would in the absence of the manual setting means. in actual embodiments of this invention this distance is of the order of 0.015 inch.

For full understanding of the invention, and further appreciation of its features and advantages, reference is to be had to the following detailed description and accompanying drawing, and to the appended claims.

in the drawing:

Figure 1 is a diagrammatic view of an electromagnetic manually-settable relay embodying this invention and shown as typically connected in a heating-control system; and

Figures 2 and 3 are views showing the relay of Fig. 1 with its parts in different positions assumed in operation.

Referring first more particularly to the burner control system shown in Fig. 1 of the drawing, the numeral 11 indicates a conduit which, it is to be assumed, is connected at its open end to a source of fuel gas; the conduit being connected at its other end to a main burner 12. In this conduit is a valve structure, generally indicated at 13, which comprises a closure 14 cooperable Patented May 6, 1958 with a valve port 15 and biased to port-closing position. In the upper part of the valve structure, above a flexible diaphragm is for guiding the closure, are electrical means (not shown) which are effective when energized to raise the closure to port-opening position. These electrical means may be of the sensitive electromagnetic type adapted to act on closure 14 either directly, or indirectly through a pilot valve controlling the fluid pressure on opposite sides of the diaphragm 16, typical examples of which are disclosed in my Patents No. 2,358,828 and No. 2,294,693, respectively.

For energizing valve 13 there is a thermoelectric generating device 1", comprising a plurality of thermocouples whose hot-junctions are in the flame 18 of a pilot burner 19, for igniting the main burner, which is connected by a pipe 26 to conduit ll ahead of the valve. One terminal of device 17 is connected by a wire 21 to one terminal of valve 13, the other terminal of the valve being connected by a wire 22 to the terminal end of a resilient switch blade 23 having a contact element 24 which cooperates with a contact element 25 carried by another resilient switch blade 2s. Blade 25 is connected by a wire 2? to one terminal of a safety limit control 28 which may be of any convenient type and is arranged to respond to a condition, such as furnace temperature or boiler pressure, resulting from the operation of the main burner the limit control having normally-closed contacts which open only upon establishment of an abnormal degree of said condition. The energizing circuit for valve is completed by a wire 3-0 which interconnects the remaining terminals of the limit control and the generating device 1'7.

For automatically actuating the switch 23--26 there is an electromagnetic device or relay, generally indicated at 31, which comprises a U-shaped core having side arms 32 and 33, an elongated armature 3d fulcrumed adjacent one of its ends on the end of core-arm 32 and having a medial portion disposed closely adjacent the end of core-arm 33 for attraction thereto, and a coil 35 wound around arm Armature 34 is biased in countercloclwise direction by the force of a spring 36, and the corearm is provided with a conventional shading ring 37.

One terminal of the relay coil 35 is connected by a wire 38 to the secondary of a step-down transformer 39 whose primary is connected to the A. C. service lines. From the secondary of the transformer another wire ill leads to one terminal of a conventional room-thermostat responsive to heat produced by the main burner and having contacts d2; the other terminal of the thermo stat being connected to the remaining terminal of the relay through a resistor 43 and a wire 44. Armature 3:4 is operatively connected to the switch blade 23 by means of a link or yoke 45, preferably of insulating material, so that upon closing of the thermostat contacts and consequent attraction of the armature, contact 24 is brought into engagement with the relatively-fixed contact 2d to complete the energizing circuit of valve 13.

Counterclockwisc movement of armature 34- under the force of bias pring 36 is limited by engagement of its right-hand end with the circular surface 46 of a mernher 47 which is mounted on the electromagnet for limited rotation about a fixed pivot 48 concentric with surface 46. Member l? is provided with a handle 49 and is biased counterclockwise by the force of a torque-spring arrangement 55? so that the handle is normally in eng gem-ant with a stop 51. The Contact blade 26 is flexed in a direction toward contact blade 23 but, while member is in the position shown in Fig. l, movement of blade 26 in that direction is limited by the engagement of its free end with a plane surface 52 of member 47.

Rotatable together with member 47 is another member- 53 pivoted at 54; a broken line 55 indicating the common connection between the members. The member 53 cooperates with another switch comprising a pair of resilient blades 55 and 57 carrying cooperating contacts 58 and 59, respectively. Blade 57 is flexed toward blade 56 but when the member 53 is in the position shown in Figs. 1 and 2 contact 59 is held apart from contact 58 due to engagement of the tip of blade 57 with a plane surface 60 of member 53. The terminals of blades 56 and 57 are connected by wires 61 to the control wires 40 and 44.

in normal operation of the system, while A. C. service exists, when the contacts 42 of the thermostat close in response to demand for heat the energizing circuit of electromagnet 31 is completed so that armature 34 is attracted and, through link 45, blade 23 is flexed downwardly and contact element 24 brought into engagement with element 25these parts then being in the positions shown in Fig. 2. The closing of contact elements 24, 25 effects completion of the energizing circuit of valve 13 so that gas is then supplied to the main burner, provided that the contacts 28 of the limit control are closed and the pilot burner is alight.

in the event of failure of the A. C. service, in order to effect operation of the burner the members 47 and 53 are manually rotated clockwise by means of handle 49 to the position shown in Fig. 3. When the members reach this position a projection 62 on the surface 46 of member 47 enters a conforming opening 63 in the armature so that, under the force of armature-spring 36, the members are held or latched in their manually-moved position. Inasmuch as the surface 46 is a surface of revolution of member 47, the position of the armature relative to the electromagnet remains the same as when the members were in their normal or unmoved position.

When the members 47, 53 are in the position of Fig. 3 their surfaces 52, 6% no longer impede upward fiexure of blades 26, 57 so that contacts 24, 25 and 58, 59 close and energization of gas valve 13 is normally effected. The closing of contacts 53, 59 establishes a low resistance circuit, independent of the room thermostat and resistor 43, interconnecting relay 31 and the secondary of transformer 39 which ensures such powerful operation of the relay upon resumption of the electric service that the armature is attracted against the additional force of blade 26 and the latching connection 62, 63 is interrupted so that-the members 47, 53 return to their normal biased position-the parts then being in the positions of Fig. l or Fig. 2 as determined by the condition of the room thermostat.

The control system shown in Fig. 1 is substantially the same as that disclosed and claimed in my copending application Serial No. 364,805 filed June 29, 1953, now Patent No. 2,734,564, granted February 14, 1956.

The specific embodiment of my invention herein shown and described is obviously susceptible of modification within departing from the spirit of the invention, and I intend therefore to be limited only by the scope of the appended claims.

I claim as my invention:

1. In combination: an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized and biased to a fixed position away from the electromagnet; switching means linked to said armature for actuation by movement thereof, said switching means being arranged for actuation by the armature to one controlling position when the armature is attracted; a member manually movable to actuate said switching means to said one position while the armature is maintained in said biased position; means biasing said member to unmoved position; and means for maintaining said member in switch-actuating position against the force of its bias comprising means forming, while the armature is in said biased position, a holding connection between the armature andsaid member.

2. In combination:. an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized and biased to a fixed position away from the electromagnet; switching means linked to said armature for actuation by movement thereof and comprising a first contact element movable with the armature and a second contact element normally fixed relative to the electromagnet and arranged so that itis engaged by said first contact element when the armature is attracted; means for actuating said switching means comprising a member manually movable to engage and effect movement of said normally-fixed contact element into engagement with said first contact element; means biasing said member to unmoved position; and means for maintaining said member in switch-actuating position against the force of its bias comprising means forming, while the armature is in said biased position, a holding connection between the armature and said member.

.3. in combination: an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized and biased to a fixed position away from the electromagnet; switching means linked.

to said armature for actuation by movement thereof and comprising a first contact element movable with the armature and a second contact element normally fixed relative to the electromagnet and arranged so that it is engaged by said first contact element when the armature is attracted; means supporting said second contact element and urging the same toward engagement with said first contact element; a movable member for actuating said switching means and having a portion normally engaged by said supportin means and thereby preventing movement of the second contact element into engagement with the first contact element when the member is in normal position; said member being biased to said normal position and manually movable to another position wherein said member-portion is free from engagement by said supporting means and said movement of the second contact element is effected; and means for maintaining said'mernber in said other position against the force of its bias comprising means forming, while the armature is in said. biased position, a holding connection between the armature and said member.

4. In combination: an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized; means biasing said armature in a direction away from the electromagnet; switching meanslinked to said armature for actuation by movement thereof, said switching means being arranged for actuation by the armature to one controlling position when the armature is attracted; a member pivotally mounted on the electromagnet and biased to a normal position; said member having a surface of revolution engaged by a portion of said armature anddetermining the biased position of the armature; said member being manually rotatable to another position to'eliect actuation of said switching means to said one position while maintaining the armature in said biased position; said surface of revolution being of such extent that, while the electromagnet is unenergized, said surface is engaged by said armature-portion when the member is rotated to said other position; and

cooperating means on said surface and said armatureportion for holding said member in said other position against the force of its bias while the electromagnet is unenergized.

5. The combina i n defined in claim 4 and wherein said means for holdisaid member in said other position comprises a latching connection between said surface and said armature-portion.

6. In combination: an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized; means biasing said armature in a direction away fro-m the electromagnet; switching means linked to said armature for actuation by movement thereof and comprising a first contact element movable with the armature and a second contact element normally fixed relative to the electromagnet and arranged so that it is engaged by said first contact element when the armature is attracted; a member pivotally mounted on the electromagnet and biased to a normal position; said member having a surface of revolution engaged by a portion of said armature and determining the biased position of the armature; said member being manually rotatable to another position to engage and effect movement of said normally-fixed contact element into engagement with said first contact element; said surface of revolution being of such extent that, while the electromagnet is unenergized, said surface is engaged by said armature-portion when the member is rotated to said other position; and cooperating means on said surface and said armature-portion for holding said member in said other position against the force of its bias whiie the electromagnet is unenergized.

7. In combination: an electromagnet; an armature mounted for attraction toward the electromagnet when the same is energized; means biasing said armature in a direction away from the electromagnet; switching means linked to said armature for actuation by movement thereof and comprising a first contact element movable with the armature and a second contact element normally fixed relative to the electromagnet and arranged so that it is engaged by said first contact element when the armature is attracted; a member pivotally mounted on the electromagnet and biased to a normal position; said member having a surface of revolution engaged by a portion of said armature and determining the biased position of the armature; means supporting said second contact element and urging the same toward engagement with said first contact element: means on said member for actuating said switching means and comprising a portion of the member normally engaged by said supporting means and thereby preventing movement of the second contact element into engagement with the first contact element when the member is in said normal position; said member being manually rotatable to another position wherein said member-portion is free from engagement by said supporting means and said movement of the second contact element is then eifected; said surface of revolution being of such extent that, while the electromagnet is unenergized, said surface is engaged by said armature-portion when the member is rotated to said other position; and cooperating means on said surface and said armature-portion for holding said member in said other position against the force of its bias while the electromagnet is unenergized.

8. The combination defined in claim 7 and wherein said means for holding said member in said other position comprises a latching connection between said surface and said armature-portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,703,056 Brockway Feb, 19, 1929 1,789,730 Demasters Jan. 20, 1931 2,057,093 Geisslinger Oct. 13, 1936 2,069,631 Thomas Feb. 2, 1937 2,091,108 Sengebusch Aug. 24, 1937 2,503,632 Prather Apr. 11, 1950 FOREIGN PATENTS 22,606 Great Britain Feb. 21, 1907 of 1906 901,749 France Nov. 13, 1944 907,793 France July 23, 1945 

